The invention generally relates to robotics and particularly relates to telerobotic surgery.
Telerobotic surgical devices are well suited for use in performing endoscopic (or minimal access) surgery, as opposed to conventional surgery where the patient""s body cavity is open to permit the surgeon""s hands access to internal organs. Endoscopic techniques involve performing an operation through small (about 5 mm to 10 mm) skin incisions through which instruments are inserted for performing the surgical procedure. A video camera may also be inserted into the patient in the area of the surgical site to view the procedure. Endoscopic surgery is typically less traumatic than conventional surgery, in part, due to the significantly reduced size of the incision. Further, hospitalization periods are shorter and recovery periods may be quicker when surgery is performed endoscopically rather than conventionally.
It is, of course, important that the surgeon have some feedback from the surgical site, e.g., visual feedback either through a camera and fiber optic cable, or through real-time computerized tomography scan imagery. Even with good visualization, however, the surgeon""s tactile and position senses are physically removed from the operative site rendering the endoscopic procedure slow and clumsy. Current instrumentation, with forceps, scissors, etc., inserted into the body at the end of long slender push rods is not fully satisfactory. The use of such conventional instrumentation may result in longer operative time, and potentially higher risks, for example if a ruptured artery cannot be quickly closed off then significant blood loss may occur. Moreover, there are limitations on the type and complexity of procedures that can be performed endoscopically due, in part, to the limitations on the instruments that may be employed.
Limited development work has been undertaken to investigate the use of robots in surgery. The robot at the surgical site, however, must be small and light enough that it may be easily manipulated around and inside of the patient, yet strong enough to perform effective surgery. The controls for the robot must also be precise and not sloppy. Presently existing telerobotic systems, using manipulators both with and without haptic feedback, are generally too bulky and heavy for many endoscopic techniques, or are too weak and imprecise for surgery.
There is a need, therefore, for a micro-manipulator that is strong and precise in its movements, yet is small, light and easily manipulated.
The invention provides an articulated apparatus that includes a first link member, a second link member, and a third link member. The second link member is coupled to the first link member at a proximal end of the second link member by a first joint having a first axis of rotation. The third link member is coupled to a distal end of the second link member by a second joint. The movement of the third link member with respect to the second link member is governed by at least one tendon that passes through the first axis of rotation of the first joint such that movement of the second member with respect to the first member does not cause movement of the third member with respect to the second member.